IOS XR – L2VPN | Fryguy's Blog

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Ok, now it is time for some L2VPN. Here we will use the same diagram as before, but instead of providing MPLS VPN between CE1 and CE2, we are going to create a L2VPN so that CE1 and CE2 think that they are directly connected to each other. This lab builds off the previous post, so the routers where already configured.

First up, CE1
CE1(config-if)#int f0/0
CE1(config-if)#ip add 10.1.34.3 255.255.255.0
CE1(config-if)#int l0
CE1(config-if)#ip add 10.1.3.3 255.255.255.255
CE1(config-if)#router ospf 1
CE1(config-router)#net 10.0.0.0 0.255.255.255 a 0
CE1(config-router)#
Now CE2
CE2(config-if)#ip add 10.1.34.4 255.255.255.0
CE2(config-if)#int l0
CE2(config-if)#ip add 10.4.4.4 255.255.255.255
CE2(config-if)#router ospf 1
CE2(config-router)#net 10.0.0.0 0.255.255.255 a 0
CE2(config-router)#

Ok, now time for the PE routers.
PE1:
First, lets reset the interface to all its defaults:
RP/0/RSP0/CPU0:PE1(config)#default interface g0/1/0/19
RP/0/RSP0/CPU0:PE1(config)#commit
Now PE2:
RP/0/RSP0/CPU0:PE2(config)#default interface g0/1/0/19
RP/0/RSP0/CPU0:PE2(config)#commit
Now, lets kill our OSPF sessions. On both routers:
PE1:
RP/0/RSP0/CPU0:PE1(config)#no router ospf 100
RP/0/RSP0/CPU0:PE1(config)#commit
PE2:
RP/0/RSP0/CPU0:PE2(config)#no router ospf 100
RP/0/RSP0/CPU0:PE2(config)#commit
OK, now we can build out L2VPN cross-connects.
Fist up, we need to get to the L2VPN configuration
RP/0/RSP0/CPU0:PE1(config)#l2vpn
Now to configure our X-Connect group
RP/0/RSP0/CPU0:PE1(config-l2vpn)#xconnect group R3R4
And our Point-to-Point settings
RP/0/RSP0/CPU0:PE1(config-l2vpn-xc)#p2p R3_to_R4
Place the interface in the P2P group R3_to_R4
RP/0/RSP0/CPU0:PE1(config-l2vpn-xc-p2p)#interface g0/1/0/19
Specify our Neighbor for this with a pseudowire ID (think of it as a circuit ID) and then commit our changes
RP/0/RSP0/CPU0:PE1(config-l2vpn-xc-p2p)#neighbor 150.2.2.2 pw-id 304
RP/0/RSP0/CPU0:PE1(config-l2vpn-xc-p2p-pw)#comm
Now, this is unique to our CE devices, we need to specify the speed in order to get the interfaces up as the CE routers here do not support Gigabit Ethernet
RP/0/RSP0/CPU0:PE2(config-if)#int g0/1/0/19
RP/0/RSP0/CPU0:PE2(config-if)#spee 100
RP/0/RSP0/CPU0:PE2(config-if)#comm
Now for PE2:
RP/0/RSP0/CPU0:PE2(config)#l2vpn
RP/0/RSP0/CPU0:PE2(config-l2vpn)#xconnect group R3R4
RP/0/RSP0/CPU0:PE2(config-l2vpn-xc)#p2p R3_to_R4
RP/0/RSP0/CPU0:PE2(config-l2vpn-xc-p2p)#interface g0/1/0/19
The Pseudo-wire ID must match.
RP/0/RSP0/CPU0:PE2(config-l2vpn-xc-p2p)#neighbor 150.1.1.1 pw-id 304
RP/0/RSP0/CPU0:PE2(config-l2vpn-xc-p2p-pw)#comm
RP/0/RSP0/CPU0:PE2(config-if)#int g0/1/0/19
RP/0/RSP0/CPU0:PE2(config-if)#spee 100
RP/0/RSP0/CPU0:PE2(config-if)#comm

Now we can look at our L2VPN Cross-connects
 RP/0/RSP0/CPU0:PE1#sh l2vpn xconnect
  Tue Apr 24 03:40:36.619 UTC
  Legend: ST = State, UP = Up, DN = Down, AD = Admin Down, UR = Unresolved,        SB = Standby, SR = Standby Ready

XConnect                Segment 1            Segment 2
  Group   Name       ST   Description     ST   Description            ST
  ---------------------   ------------------   -------------------------
  R3R4    R3_to_R4   UP   Gi0/1/0/19      UP   150.2.2.2       304    UP
  ----------------------------------------------------------------------
  RP/0/RSP0/CPU0:PE1#

There you go, that looks good. Now, can we PING between CE1 and CE2?
CE1#p 10.1.34.4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.34.4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

Yup, PING works.  Hmm, wonder what CDP looks like?
 CE1#sh cdp nei
  Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
  S - Switch, H - Host, I - IGMP, r - Repeater

Device ID    Local Intrfce   Holdtme  Capability  Platform  Port ID
  CE2          Fas 0/0         160      R S I       2811      Fas 0/0
  CE1#

Now if we look at OSPF:
CE1#sh ip ospf neighbor

Neighbor ID   Pri   State     Dead Time   Address     Interface
  10.4.4.4        1   FULL/DR   00:00:33    10.1.34.4   FastEthernet0/0

All neighbored up! That means we should be able to PING between loopback interfaces:
CE1#p 10.4.4.4 so l0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.4.4.4, timeout is 2 seconds:
Packet sent with a source address of 10.1.3.3
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
CE1#

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